2018_-__El_Capitan_Bridge_Underwater_Final_Report.pdf

UNDERWATER BRIDGE INSPECTION REPORT

EL CAPITAN BRIDGE

EL CAPITAN CROSSOVER OVER MERCED RIVER

YOSEMITE NATIONAL PARK

STRUCTURE NO. 8800-002P

INSPECTION TYPE: UNDERWATER

INSPECTION DATE: 8/18/2018

Report prepared for: Report prepared by:

Federal Highway Administration Collins Engineers, Inc.

Federal Lands Bridge Office 10201 Fairfax Blvd, Suite 530 Bridge Inspection and Management Program Fairfax, VA 22030 21400 Ridgetop Circle Sterling, Virginia 20166

Engineer of Record

11/16/18 kstevens New Stamp

STRUCTURE SUMMARY STRUCTURE NO. 8800-002P

EL CAPITAN BRIDGE U/W INSPECTION DATE: 8/18/2018

INSPECTION TEAM & METHOD

The El Capitan Bridge carries El Capitan Crossover over the Merced River in Yosemite National Park. The bridge is a three-span structure consisting of steel beams supported by two concrete piers and two concrete abutments. The piers and abutments are faced with stone masonry. Based on available design drawings, the piers and abutments are supported by concrete footings on timber piles. The structure has been designated as scour critical.

At the time of inspection (12:00 PM on 8/18/2018), the water level was located approximately 15.6

ft. below the top of deck at the north nose of Pier #1. For the purposes of this report, Abutment #1 was located at the east end of the bridge, Abutment #2 was located at the west end of the bridge, and the piers were numbered 1 and 2 from east to west.

The underwater inspection was performed on August 18, 2018. The underwater inspection was conducted by a three-person team consisting of a professional engineer-diver and team leader (Daniel Stromberg, P.E.), one engineer-diver (John Strub, E.I.T.), and one technician-diver (Matthew Stromberg). The inspection was performed using commercial scuba equipment. During the inspection, the divers worked from shore and a note taker on the east and west shorelines recorded the inspection notes.

The underwater inspection consisted of a Level I visual and tactile examination on the substructure units from the waterline to the channel bottom with particular attention given to any observed areas of excessive deterioration or apparent distress. Level II inspection, which consisted of a detailed inspection at the waterline, mid-depth, and at the channel bottom were conducted on all of the various faces of the substructure units. At each Level II location, a 12 in.

by 12 in. area of aquatic growth was removed so that the substrate condition could be more closely examined. In areas of observed deficiencies, the substructure surface was sufficiently cleaned to determine the extents of the deficiency. The type of channel bottom material, the presence or extent of scour and/or shoreline protection, the presence or extent of drift and debris, and observed scour conditions were noted. Underwater photographs of the various defect/deficiencies were taken with various forms of equipment.

SUMMARY OF FINDINGS

Overall, the submerged substructure units are in Fair Condition (NBI Condition Rating = 5).

Aquatic growth up to 1/4 in. thick was observed from the channel bottom to the waterline on the submerged surfaces. This growth consisted of algae covering 100 percent of the substructure’s submerged surface area. The following sections present the finding for each substructure unit inspected.

Abutment #1

Abutment #1 was found to be in Satisfactory Condition with only three structural deficiencies observed. Since the 2013 inspection, the length of foundation exposure has remained the same, however the maximum vertical exposure has increased. The specific deficiencies of note observed at Abutment #1 are presented in the following table:

Deficiency Location Description Random cracks Mortar joints of stone facing Hairline to 1/8” wide

Moderate scaling Exposed concrete footing surfaces

Typical 1/4” deep, and up to 1/2” deep with exposed aggregate

Exposure of vertical and horizontal faces of concrete footing

15’ north of south end to north end and around northwest corner to shoreline

Maximum vertical exposure is 4’ approximately 5’ from northwest corner; horizontal face is fully exposed within limits of vertical exposure.

Design height of foundation is 14’ and footing is founded on piles

Refer to page 8 of 26 in the Substructure Drawings Section for detailed underwater inspection notes for Abutment #1.

Pier #1

Pier #1 was found to be in Fair Condition with four structural deficiencies observed. Since the 2013 inspection there has been a significant drop in channel bottom elevation along the west and downstream sides of the pier due to scour and overall degradation of the channel bottom. In addition, there was a very heavy accumulation of timber drift debris around the upstream end of the pier and along the west side of the pier extending into the span towards Pier#2. The specific deficiencies of note observed in Pier #1 are presented in the following table:

Deficiency Location Description Random cracks Mortar joints of stone facing Hairline to 1/4” wide, to 3’ above the waterline.

Random gaps/voids Mortar joints in stone facing Gaps up to 3/4" wide with up to 8" penetration, from 3' above waterline to channel bottom or top of footing

Timber debris East face, beginning 10’ north of north nose and extending to midpoint of west face, extending through center span to Pier#2

Very heavy accumulation with logs up to 2' in dia.

Exposed vertical timber formwork

Along the entire west and south faces. On the East face, beginning 5’ south of south face and extending 15' north

2.5’ from pier faces and extending above channel bottom up to 4’ on the east face and up to 6.5’ on the west and south faces.

Refer to pages 9-10 of 26 in the Substructure Drawings Section for detailed underwater inspection notes for Pier #1.

Pier #2

Pier #2 was found to be in Fair Condition with four structural deficiencies observed, although there was also a very significant condition related to extensive scour and channel bottom degradation that has undermined the footing within a considerable portion at the south end of the pier. Since the 2013 inspection, the partial exposure of the east horizontal footing face within an area of vertical timber formwork has increased to now include the majority of the east face, the south (downstream) face, and the southerly end of the west face. Across the southerly end of the east face and most of the south face, the timber planking has been washed away leaving the footing face exposed, with much of the downstream half of the footing undermined and exposing the underlying timber piles. Refer to Channel Bottom section for more undermining details. The specific deficiencies of note observed in Pier #2 are presented in the following table:

Deficiency Location Description Random cracks Mortar joints of stone facing Hairline to 1/8” wide, to 3’ above waterline Random gaps/voids Mortar joints in stone facing Gaps up to 3/4" wide with up to 8" penetration, from 3' above waterline to channel bottom or top of footing

Partial exposure of concrete footing and undermining (exposed timber formwork at various locations)

East face starting 5’ south of north end, to across entire south face, and west face to 10’ north of south end.

Footing exposed and undermined for 16’ on south end of east face and 5’ on east end of south face, up to 3’ vertical and full footing width (timber piles exposed)

Timber debris East and north faces.

Beginning at west shoreline, 20' north of north nose and extending to south ¼ point of east face

Very heavy accumulation with logs up to 2' dia.

Refer to pages 11-13 of 26 in the Substructure Drawings Section for detailed underwater inspection notes for Pier #2.

Abutment #2

Abutment #2 was found to be in Satisfactory Condition with four structural deficiencies observed, but no new deficiencies since the 2013 inspection. The specific findings of note observed in Abutment #2 are presented in the following table:

Deficiency Location Description Random cracks Mortar joints of stone facing Hairline to 1/8” wide, from 3' above waterline to channel bottom

Partial concrete footing exposure (partial vertical exposure due to vertical timber formwork and sand infilling)

4’ south of the north end, extending to south end and around southeast corner to shoreline

Maximum vertical exposure is 4’-8” (formwork) at southeast corner, full horizontal face exposure for full length.

Design height of footing is 14’ and foundation is founded on piles

Exposed vertical timber formwork

4’ south of north end and extending to south end

2.5’ from breast wall and extending above channel bottom up to approximately 5’

Refer to page 14 of 26 in the Substructure Drawings Section for detailed underwater inspection notes for Abutment #2.

Channel Bottom

The channel and channel protection are rated in Poor Condition (NBI Condition Rating = 4). The channel embankments are stable.

Significant overall channel degradation and localized scour has occurred at the bridge along the west side and around the downstream (south) end of Pier#1, along the east side and around the downstream (south) end of Pier#2, and throughout the span between the piers. Generally, channel bottom elevations have dropped in these areas between 6’ and 13’, with a maximum drop of approximately 9.5’ at Pier#1 (downstream, west side) and a maximum drop of approximately 13’ at the West Pier (downstream, east side). The channel bottom drop along Pier#1 has now exposed the vertical footing planking along the downstream (south) and entire west sides of the pier. The channel bottom drop along Pier#2 has now exposed the vertical footing planking along most of the east side and around the downstream (south) end of the pier, with some of the planking around the southeast corner missing and exposing a rough concrete footing that is undermined. From the southeast corner (downstream east), the footing is undermined its full width (±11’) to the west and for approximately 17’ to the north. The maximum vertical height of the undermining is approximately 3’. It is estimated that as much as one-third of the overall footing could be undermined. Within the undermining, three piles could be encountered by the diver along the outer edge of the footing with others felt with probing with a sounding rod. Three piles along the perimeter of the footing are sound and well embedded in footing underside with approximately 3’ of vertical exposure of the piles. The degradation/scour condition and undermining of Pier#2 is a significant condition, but at the moment does not appear to be a critical situation since the Pier#2 footing is pile supported. Apparently, one or more significant flow events has occurred since the 2013 inspection and produced a significant drop in the channel bottom in the entire span between the piers and around the downstream end of each pier. The upstream nose of each pier has riprap up to 4’ in diameter that appears to have prevented any appreciable drop in channel bottom elevation at the upstream ends. It should be noted that there is a heavy drift accumulation in much of the waterway between the two piers.

Evaluations and Recommendations

Overall, the substructure units of the El Capitan Bridge collectively were observed to be in Fair Condition below the high-water line with significant erosion-related deficiencies and localized scour around the two piers.

Localized scour and general channel degradation has developed significantly since the 2013 inspection. Generally, channel bottom elevations have dropped in these areas between 6’ and 13’, with a maximum drop of approximately 9.5’ at Pier#1 (downstream, west side) and a maximum drop of approximately 13’ at the West Pier (downstream, east side). The channel bottom drop along Pier#1 has now exposed the vertical footing planking along the downstream (south) and entire west sides of the pier. The channel bottom drop along Pier#2 has now exposed the vertical footing planking around the downstream (south) end of the pier, with some of the planking missing and exposing a rough concrete footing that is undermined, with up to an estimated one-third of the downstream end of the footing undermined and exposing the underlying timber piles. Since the Pier#2 footing is pile supported there should still be considered vertical support afforded to the pier; however, available design and/or as-built plans should be reviewed, and the effect of the undermining and pile exposure should be examined with respect to any reduction in pier load carrying capacity. It is recommended that properly designed riprap be installed around the entire perimeter of each pier, along with a complete filling of the undermining cavity at Pier#2. Available as-builts and/or design plans should be reviewed for the effect of the undermining and pile exposure at Pier#2 with respect to any reduction in the pier load carrying capacity and monitor the bridge after any significant flow events until the undermining conditions are addressed.

Lastly, the heavy accumulation of timber debris in the channel between Abutment#2 and Pier#1 could increase significantly if there is a significant storm or high flow event, therefore it is recommended that the timber debris around each pier be removed to prevent further and possibly more detrimental accumulation.

Finally, in accordance with NBIS based on the current scour/degradation concerns at the bridge, it is recommended that an underwater inspection of the bridge be performed at intervals not to exceed 24 months.

Inspection Team Leader: QA/QC Review:

10/26/2018 10/26/2018 Daniel G. Stromberg, P. E Date Charles H. Conrad P.E. Date

SUBSTRUCTURE DRAWINGS

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UNDERWATER INSPECTION

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EL CAPITAN BRIDGE PLAN

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STRUCTURE NO. 8800-002P

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OF

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INSPECTION DATE: 8/18/2018

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ABUTMENT#1

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PIER#1

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PIER#2

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ABUTMENT#2

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TIMBER FORMWORK (TYP.)

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4'-6' DEEP SCOUR AREA

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APPROXIMATE 4' RIPRAP LIMITS (TYP.)

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DRIFT (TYP.)

GENERAL NOTES: 1. AT THE TIME OF INSPECTION ON AUGUST 18, 2018, THE WATERLINE WAS LOCATED 15.6' AT THE TIME OF INSPECTION ON AUGUST 18, 2018, THE WATERLINE WAS LOCATED 15.6' BELOW THE TOP OF CURB AT THE UPSTREAM NOSE OF PIER#1. 2. FOR THE PURPOSES OF THIS REPORT, ABUTMENT#1 WAS LOCATED AT THE EAST END OF THE FOR THE PURPOSES OF THIS REPORT, ABUTMENT#1 WAS LOCATED AT THE EAST END OF THE BRIDGE, ABUTMENT#2 AT THE WEST END OF THE BRIDGE, AND THE PIERS WERE NUMBERED 1 AND 2 FROM EAST TO WEST. 3. SOUNDINGS INDICATE THE WATER DEPTHS AT THE TIME OF INSPECTION AND ARE MEASURED IN SOUNDINGS INDICATE THE WATER DEPTHS AT THE TIME OF INSPECTION AND ARE MEASURED IN FEET. 4. GENERALLY THERE IS RIPRAP MEASURING UP TO 4' IN DIAMETER ALONG BOTH ABUTMENTS GENERALLY THERE IS RIPRAP MEASURING UP TO 4' IN DIAMETER ALONG BOTH ABUTMENTS AND AT THE UPSTREAM NOSES OF EACH PIER. THERE IS MINIMAL, IF ANY, LARGE RIPRAP AROUND THE REMAINDER OF THE PIERS. THE UPSTREAM SPAN BETWEEN THE PIERS WAS INACCESSIBLE DUE TO VERY HEAVY DRIFT.

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UNDERWATER INSPECTION

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ABUTMENT#1 (WEST ELEVATION)

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STRUCTURE NO. 8800-002P

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GENERAL CONDITION RATING: SATISFACTORY (6)

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OF

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INSPECTION DATE: 8/18/2018

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LEGEND: =INSPECTION NOTE

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INSPECTION NOTES: 1. VERTICAL AND HORIZONTAL FOUNDATION EXPOSURE FROM 15' NORTH OF THE SOUTH END TO VERTICAL AND HORIZONTAL FOUNDATION EXPOSURE FROM 15' NORTH OF THE SOUTH END TO THE NORTH END AND AROUND THE NORTHWEST CORNER TO SHORELINE. MAXIMUM VERTICAL EXPOSURE WAS 4' HIGH AND WAS LOCATED APPROXIMATELY 5' FROM THE NORTHWEST CORNER. 2. RANDOM HAIRLINE TO " WIDE CRACKING IN THE STONE MORTAR JOINTS. RANDOM HAIRLINE TO " WIDE CRACKING IN THE STONE MORTAR JOINTS. 18" WIDE CRACKING IN THE STONE MORTAR JOINTS. 3. MODERATE SCALING ON EXPOSED CONCRETE SURFACES, " TYPICAL, BUT UP TO " DEEP, MODERATE SCALING ON EXPOSED CONCRETE SURFACES, " TYPICAL, BUT UP TO " DEEP, 14" TYPICAL, BUT UP TO " DEEP, 12" DEEP, WITH EXPOSED AGGREGATE. 4. TIMBER DEBRIS CONSISTING OF TREES AND BRANCHES, MEASURING UP TO 8" IN DIAMETER TIMBER DEBRIS CONSISTING OF TREES AND BRANCHES, MEASURING UP TO 8" IN DIAMETER WAS OBSERVED ON TOP OF THE ABUTMENT BETWEEN THE GIRDER LINES. GENERAL NOTES: 1. CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER ALONG THE MAJORITY OF THE CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER ALONG THE MAJORITY OF THE ABUTMENT LENGTH WITH AREAS OF SAND ALLOWING UP TO 8" OF PROBE ROD PENETRATION. 2. THE SOUTH 5' OF THE ABUTMENT IS DRY.THE SOUTH 5' OF THE ABUTMENT IS DRY.

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UNDERWATER INSPECTION

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PIER#1 (EAST ELEVATION)

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STRUCTURE NO. 8800-002P

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GENERAL CONDITION RATING: FAIR (5)

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OF

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INSPECTION DATE: 8/18/2018

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LEGEND: =INSPECTION NOTE

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AutoCAD SHX Text INSPECTION NOTES: 1. RANDOM HAIRLINE TO " WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" DEEP RANDOM HAIRLINE TO " WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" DEEP 14" WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" DEEP 34" WIDE BY UP TO 8" DEEP IN THE STONE FACING MORTAR JOINTS FROM THE CHANNEL BOTTOM TO 3' ABOVE THE WATERLINE. 2. VERY HEAVY ACCUMULATION OF TIMBER DEBRIS UP TO 2" IN DIAMETER, EXTENDING 10' NORTH VERY HEAVY ACCUMULATION OF TIMBER DEBRIS UP TO 2" IN DIAMETER, EXTENDING 10' NORTH OF THE UPSTREAM NOSE AND ALONG MOST OF THE WEST FACE, EXTENDING OUT 10' OR MORE FROM THAT FACE. 3. AREA OF LOCAL SCOUR, APPROXIMATELY 4' TO 6' DEEP. AREA OF LOCAL SCOUR, APPROXIMATELY 4' TO 6' DEEP. 4. VERTICAL TIMBER FORMWORK BEGINNING 5' SOUTH OF THE NORTH NOSE ON THE WEST SIDE, VERTICAL TIMBER FORMWORK BEGINNING 5' SOUTH OF THE NORTH NOSE ON THE WEST SIDE, EXTENDING AROUND PIER TO 15' NORTH OF SOUTH NOSE ON EAST SIDE AND LOCATED 2.5' FROM THE PIER FACES. MAXIMUM PROJECTIONS ABOVE CHANNEL BOTTOM ARE APPROXIMATELY 4' TO 6' AND SAND INFILL IS PRESENT BETWEEN FORMWORK AND PIER. GENERAL NOTES: 1. CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER WITH SAND INFILL, ALLOWING CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER WITH SAND INFILL, ALLOWING NO PROBE ROD PENETRATION, PRIMARILY AROUND THE UPSTREAM (NORTH) NOSE. THERE IS AN AREA OF RANDOM RIRAP MEASURING UP TO 30" DIAMETER ALONG THE EAST FACE THAT EXTENDS TO THE SOUTH POINT. OTHERWISE, CHANNEL BOTTOM WAS PRIMARILY A COMBINATION OF 14 POINT. OTHERWISE, CHANNEL BOTTOM WAS PRIMARILY A COMBINATION OF SAND, RIVER ROCK AND COBBLES ALLOWING MINIMAL PROBE ROD PENETRATION.

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PLAN

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4' RIPRAP

PIER 1 - PIER SHAFT

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UNDERWATER INSPECTION

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PIER#1 (WEST ELEVATION)

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STRUCTURE NO. 8800-002P

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GENERAL CONDITION RATING: FAIR (5)

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INSPECTION DATE: 8/18/2018

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LEGEND: =INSPECTION NOTE

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4' RIPRAP

INSPECTION NOTES: 1. RANDOM HAIRLINE TO " WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" RANDOM HAIRLINE TO " WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" 14" WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" 34" WIDE BY UP TO 8" DEEP IN THE STONE FACING MORTAR JOINTS FROM THE CHANNEL BOTTOM TO 3' ABOVE THE WATERLINE. 2. HEAVY ACCUMULATION OF TIMBER DEBRIS UP TO 2' IN DIAMETER, ALONG THE ENTIRE WEST HEAVY ACCUMULATION OF TIMBER DEBRIS UP TO 2' IN DIAMETER, ALONG THE ENTIRE WEST FACE OF THE PIER, EXTENDING FROM WATERLINE TO 4.5' BELOW THE WATERLINE AND EXTENDING INTO SPAN TO PIER#2. 3. VERTICAL TIMBER FORMWORK BEGINNING 5' SOUTH OF THE NORTH NOSE ON THE WEST SIDE, VERTICAL TIMBER FORMWORK BEGINNING 5' SOUTH OF THE NORTH NOSE ON THE WEST SIDE, EXTENDING AROUND PIER TO 15' NORTH OF SOUTH NOSE ON EAST SIDE AND LOCATED 2.5' FROM THE PIER FACES. MAXIMUM PROJECTIONS ABOVE CHANNEL BOTTOM ARE APPROXIMATELY 4' TO 6' AND SAND INFILL IS PRESENT BETWEEN FORMWORK AND PIER. GENERAL NOTES: 1. CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER WITH SAND INFILL, ALLOWING CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER WITH SAND INFILL, ALLOWING NO PROBE ROD PENETRATION, PRIMARILY AROUND THE UPSTREAM (NORTH) NOSE. OTHERWISE, CHANNEL BOTTOM WAS PRIMARILY A COMBINATION OF SAND, RIVER ROCK AND COBBLES ALLOWING MINIMAL PROBE ROD PENETRATION.

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UNDERWATER INSPECTION

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PIER#2 (EAST ELEVATION)

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STRUCTURE NO. 8800-002P

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GENERAL CONDITION RATING: FAIR (5)

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INSPECTION DATE: 8/18/2018

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LEGEND: =INSPECTION NOTE

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PLAN

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4' RIPRAP

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PIER 2 - PIER SHAFT

INSPECTION NOTES: 1. RANDOM HAIRLINE TO " WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" DEEP RANDOM HAIRLINE TO " WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" DEEP 14" WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" DEEP 34" WIDE BY UP TO 8" DEEP IN THE STONE FACING MORTAR JOINTS FROM THE CHANNEL BOTTOM OR TOP OF FOOTING TO 3' ABOVE THE WATERLINE. 2. VERY HEAVY ACCUMULATION OF TIMBER DEBRIS CONSISTING OF LOGS UP TO 2' IN DIAMETER, VERY HEAVY ACCUMULATION OF TIMBER DEBRIS CONSISTING OF LOGS UP TO 2' IN DIAMETER, START AT THE WEST SHORELINE, 20' NORTH OF THE UPSTREAM NOSE, AND EXTENDING ALONG THE FACE TO THE SOUTH POINT. 14 POINT. 3. VERTICAL TIMBER FORMWORK IS PRESENT FROM APPROXIMATELY 5' SOUTH OF THE DOWNSTREAM VERTICAL TIMBER FORMWORK IS PRESENT FROM APPROXIMATELY 5' SOUTH OF THE DOWNSTREAM NOSE TO WITHIN 5' OF THE UPSTREAM NOSE AND IS LOCATED 2.5' OFF THE EAST FACE. THE FORMWORK PROTRUDES A MAXIMUM OF APPROXIMATELY 13' ABOVE THE CHANNEL BOTTOM. 4. AREA OF LOCAL SCOUR RANGING FROM APPROXIMATELY 4' TO 8' DEEP. AREA OF LOCAL SCOUR RANGING FROM APPROXIMATELY 4' TO 8' DEEP. 5. THERE IS FOOTING UNDERMINING AND PILE EXPOSURE ALONG APPROXIMATELY 30% OF THE EAST THERE IS FOOTING UNDERMINING AND PILE EXPOSURE ALONG APPROXIMATELY 30% OF THE EAST FACE. THE VERTICAL EXPOSURE STARTS APPROXIMATELY 16' NORTH OF THE SOUTHEAST CORNER AND EXTENDS AROUND THE DOWNSTREAM NOSE FOR APPROXIMATELY 5'. THERE WAS APPROXIMATELY 3' OF CLEARANCE BETWEEN THE BOTTOM OF FOOTING AND THE CHANNEL BOTTOM AT THE SOUTHEAST CORNER WITH NUMEROUS TIMBER PILES EXPOSED. GENERAL NOTES: 1. CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER WITH SAND INFILL, ALLOWING NO CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER WITH SAND INFILL, ALLOWING NO PROBE ROD PENETRATION, PRIMARILY AROUND THE UPSTREAM (NORTH) NOSE. OTHERWISE, CHANNEL BOTTOM WAS PRIMARILY A COMBINATION OF SAND, RIVER ROCK AND COBBLES ALLOWING MINIMAL PROBE ROD PENETRATION.

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UNDERWATER INSPECTION

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PIER#2 (WEST ELEVATION)

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STRUCTURE NO. 8800-002P

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GENERAL CONDITION RATING: FAIR (5)

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OF

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INSPECTION DATE: 8/18/2018

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LEGEND: =INSPECTION NOTE

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4' RIPRAP

INSPECTION NOTES: 1. RANDOM HAIRLINE TO " WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" RANDOM HAIRLINE TO " WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" 14" WIDE CRACKING AND VOIDS/GAPS UP TO " WIDE BY UP TO 8" 34" WIDE BY UP TO 8" DEEP IN THE STONE FACING MORTAR JOINTS FROM THE CHANNEL BOTTOM OR TOP OF FOOTING TO 3' ABOVE THE WATERLINE. 2. HEAVY ACCUMULATION OF TIMBER DEBRIS CONSISTING OF LOGS UP TO 2' IN DIAMETER, HEAVY ACCUMULATION OF TIMBER DEBRIS CONSISTING OF LOGS UP TO 2' IN DIAMETER, STARTING AT THE WEST SHORELINE, EXTENDING 20' NORTH OF THE UPSTREAM NOSE, AND CONTINUING AROUND THE EAST FACE OF THE PIER. 3. 3. THERE IS TIMBER FORMWORK AT THE DOWNSTREAM NOSE AND EXTENDING APPROXIMATELY 3. THERE IS TIMBER FORMWORK AT THE DOWNSTREAM NOSE AND EXTENDING APPROXIMATELY THERE IS TIMBER FORMWORK AT THE DOWNSTREAM NOSE AND EXTENDING APPROXIMATELY 10' NORTH ALONG THE WEST FACE OF THE PIER. THE FORMWORK PROTRUDES A MAXIMUM OF APPROXIMATELY 6' OUT OF THE CHANNEL BOTTOM AT THE SOUTHWEST CORNER. GENERAL NOTES: 1. CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER WITH SAND INFILL, ALLOWING CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER WITH SAND INFILL, ALLOWING NO PROBE ROD PENETRATION, PRIMARILY AROUND THE UPSTREAM (NORTH) NOSE. OTHERWISE, CHANNEL BOTTOM WAS PRIMARILY A COMBINATION OF SAND, RIVER ROCK AND COBBLES ALLOWING MINIMAL PROBE ROD PENETRATION.

A-A

B-B

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EL CAPITAN BRIDGE

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UNDERWATER INSPECTION

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PIER#2 DETAILS

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STRUCTURE NO. 8800-002P

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GENERAL CONDITION RATING: FAIR (5)

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OF

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INSPECTION DATE: 8/18/2018

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LEGEND: =INSPECTION NOTE

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AutoCAD SHX Text INSPECTION NOTES: 1. THE EXPOSED CONCRETE FOOTING IS ROUGH AND IRREGULAR DUE TO SECTION LOSS TYPICALLY THE EXPOSED CONCRETE FOOTING IS ROUGH AND IRREGULAR DUE TO SECTION LOSS TYPICALLY UP TO 6" DEEP WITH NO EXPOSED REINFORCEMENT OBSERVED. THERE WERE ALSO RANDOM VERTICAL AND HORIZONTAL TIMBERS ALONG FACES THAT WERE ORIGINALLY BEHIND VERTICAL TIMBER FORMWORK.

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EXPOSED TIMBER PILE (TYP.)

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PIER 2 - PIER SHAFT

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= ESTIMATED UNDERMINING LIMITSESTIMATED UNDERMINING LIMITS

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EXPOSED TIMBER FORMWORK

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SECTION B-B (LOOKING WEST)

SECTION A-A (LOOKING NORTH)

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UNDERWATER INSPECTION

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ABUTMENT#2 (EAST ELEVATION)

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STRUCTURE NO. 8800-002P

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GENERAL CONDITION RATING: SATISFACTORY (6)

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OF

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INSPECTION DATE: 8/18/2018

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LEGEND: =INSPECTION NOTE

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FLOW

INSPECTION NOTES: 1. RANDOM HAIRLINE TO " WIDE CRACKING IN THE STONE MORTAR JOINTS TO 3' ABOVE THE RANDOM HAIRLINE TO " WIDE CRACKING IN THE STONE MORTAR JOINTS TO 3' ABOVE THE 18" WIDE CRACKING IN THE STONE MORTAR JOINTS TO 3' ABOVE THE WATERLINE. 2. PARTIAL FOUNDATION EXPOSURE FROM 4' SOUTH OF THE NORTH END TO THE SOUTH END PARTIAL FOUNDATION EXPOSURE FROM 4' SOUTH OF THE NORTH END TO THE SOUTH END AND AROUND THE SOUTHEAST CORNER TO SHORELINE. 3. 3. VERTICAL TIMER FORMWORK BEGINNING 4' SOUTH OF THE NORTH END AND EXTENDING TO 3. VERTICAL TIMER FORMWORK BEGINNING 4' SOUTH OF THE NORTH END AND EXTENDING TO VERTICAL TIMER FORMWORK BEGINNING 4' SOUTH OF THE NORTH END AND EXTENDING TO THE SOUTH END, AND LOCATED 2.5' FROM THE FACE. PROJECTION ABOVE THE CHANNEL BOTTOM IS UP TO APPROXIMATELY 5'. GENERAL NOTES: 1. CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER FROM THE MIDPOINT OF CHANNEL BOTTOM CONSISTED OF RIPRAP UP TO 4' IN DIAMETER FROM THE MIDPOINT OF BREASTWALL AND EXTENDED APPROXIMATELY 10' NORTH OF THE WINGWALL ALONG SHORELINE. CHANNEL BOTTOM ALONG THE SOUTH END OF THE ABUTMENT CONSISTED OF RIVER STONE AND COBBLES UP TO 1' IN DIAMETER WITH NO PROBE ROD PENETRATION (APPEARED TO BE RIPRAP BELOW TO LAYER OF COBBLES).

PHOTOGRAPHS

PHOTOGRAPHS STRUCTURE NO. 8800-002P

PHOTO #1 – NORTH (UPSTREAM) ELEVATION, LOOKING SOUTH

PHOTO #2 – SOUTH (DOWNSTREAM) ELEVATION, LOOKING NORTH

PHOTO #1 – UPSTREAM CHANNEL, LOOKING NORTH

PHOTO #2 – DOWNSTREAM CHANNEL, LOOKING SOUTH

PHOTO #5 – WEST ELEVATION OF ABUTMENT#1, LOOKING NORTHEAST

PHOTO #6 – EAST ELEVATION OF PIER#1, LOOKING NORTH

PHOTO #7 – WEST ELEVATION OF PIER#1, LOOKING NORTH

PHOTO #8 – EAST ELEVATION OF PIER#2, LOOKING NORTH

PHOTO #9 – WEST ELEVATION OF PIER#2, LOOKING NORTH

PHOTO #10 – EAST ELEVATION OF ABUTMENT#2

PHOTO #11 – TYPICAL CONCRETE CONDITION ABOVE THE WATERLINE AT

ABUTMENT#1

PHOTO #12 – TYPICAL EXPOSED TIMBER FORMWORK AT PIER#1

PHOTO #13 – PIER#2 UNDERMINING (SOUTH END)

PHOTO #14 – EXPOSED TIMBER PILE AND UNDERMINING AT PIER#2

PHOTO #15 – VERTICAL EXPOSURE OF PIER#2 FOOTING (SOUTH END)

PHOTO #16 – UNDERMINING AT THE SOUTHEAST CORNER OF PIER#2 FOOTING

PHOTO #17 – TYPICAL EXPOSED TIMBER FORMWORK AT ABUTMENT#2

NBI CONDITION RATING TABLE

NBI CONDITION RATING TABLE STRUCTURE NO. 8800-002P

9 EXCELLENT CONDITION Preservation/Cyclic Maintenance

8 VERY GOOD CONDITION—No problems noted.

7 GOOD CONDITION—Some minor problems.

SATISFACTORY CONDITION—Structural elements show some minor deterioration.

Preservation/ Condition‐Based Maintenance

FAIR CONDITION—All primary structural elements are sound but may have some minor section loss, cracking, spalling, or scour.

POOR CONDITION—Advanced section loss, deterioration, spalling, or scour.

Rehabilitation or Replacement

3 SERIOUS CONDITION—Loss of section, deterioration, spalling or scour have seriously affected primary structural components. Local failures are possible.

Fatigue cracks in steel or shear cracks in concrete may be present.

CRITICAL CONDITION—Advanced deterioration of primary structural elements.

Fatigue cracks in steel or shear cracks in concrete may be present, or scour may have removed substructure support. Unless closely monitored, the bridge may have to be closed until corrective action is taken.

IMMINENT FAILURE CONDITION—Major deterioration or section loss present in critical structural components, or obvious vertical or horizontal movement affecting structure stability. Bridge is closed to traffic, but corrective action may put it back in light service.

FAILED CONDITION—Out of service. Bridge is beyond corrective action